As a prior art of this technical area, there is an invention of “A bar type corona discharged electrostatic eliminator equipped with air vessel using pulse AC high voltage power source” filed with the Korean Intellectual Property Office on 13 Aug. 2004 by the patent application number 10-2004-64064. As other prior arts, there are Korean patent gazette publication number 10-2003-3523 (Apparatus for removing an static electricity by high frequency voltage), Japanese patent gazette publication number P2001-35686 (DC static eliminator), Japanese patent gazette publication number P2002-216994 (Pulse AC type static eliminator), etc.
The previous bar type ionizers had various defects. First, it was very inconvenient to see various information indicated at the bar (for example, bar address, frequency, duty rate, alarm, run/stop state) since the information was shown by LED instead of characters. And controlling this information was possible only by special monitoring equipment instead of a bar itself. Furthermore, ions were not generated sufficiently because of particles like dust stuck on the end of the needle inside of the tip.